Method for imparting a permanent crease to wool



United States Patent 3,345,195 METHOD FOR IMPARTING A PERMANENT GREASE T0 WOOL Billy G. Simpson, Greensboro, N.C., assignor to Dow Corning Corporation, Midland, Mich., a corporation of Michigan No Drawing. Filed Sept. 16, 1963, Ser. No. 309,301 6 Claims. (Cl. 117-10) This invention relates to a method of rendering wool permanently crease resistant.

There are several products presently being employed to render wool garments permanently crease resistant. These materials are, in general, sulfites which apparently react with wool and cause a permanent deformation to take place when the wool is creased. However, such treatments suffer from several disadvantages in that the sulfites have objectionable odors and that they adversely affect certain dyes. In addition, the sulfite treatment does not impart any additional water repellency to the wool. Thus, it is highly advantageous to provide a treatment which will render wool permanently crease resistant without adverse odors or adverse effect on the color of the wool.

It has long been known that wool could be treated with various siloxanes or hydrolyzable silanes in order to render the wool water repellent or to reduce the shrinkage of the wool during washing. However, these previous organosilicon treatments imparted little or no permanent crease resistance. Apparently the slight amount of crease resistance which is often imparted is due to the fact that the siloxanes prevented the wool from wetting as fast as untreated wool. However, the present invention does not in any way relate to the phenomena of water repellency or improved shrink resistance. Thus, it is most unexpected when applicant found that the particular treatments shown below provide a crease resistance equal to or superior to the present sulfite treatments. This is accomplished without the deleterious effects above mentioned.

The object of this invention is to provide an economical method of rendering wool permanently crease resistant Without imparting undesirable features to the wool. Other objects and advantages will be apparent from the following description.

This invention relates to a method of imparting a permanent crease to a wool fabric which comprises applying to the fabric a water solution of an organosilicon compound having on the average per silicon atom of from 1 to 2 inclusive aliphatic hydrocarbon radicals of from 1 to 3 carbon atoms inclusive attached to the silicon through silicon-carbon bond, there being on the average no more than 3 carbon atoms per silicon atom, the remaining valences of the silicon being satisfied by OH groups or SiOSi linkages, said solution containing from .1 to 10 percent by weight of the organosilicon compound based on the weight of the solution and thereafter creasing the fabric under heat and pressure.

In carrying out the method of this invention one wets the wool fabric with the aqueous solution and thereafter creases the fabric in the desired places. It is not necessary that an entire garment be wet but only that area in which the garment is to be creased. The treated wool can be first dried and then creased but often it is advantageous to crease the fabric before drying.

The temperature and pressure applied to the fabric to obtain the crease is not critical and, in general, those obtained by steam irons or in commercial pressing establishments are sufiicient.

The water solutions employed in this invention are solutions of high hydroxylated silanols or siloxanols in Ice which there is sufficient silicon-bonded hydroxyl groups to maintain the organosilicon compound in solution. The structure of these materials is not precisely known but the silyl units can be any having the defined hydrocarbon groups attached thereto such as CH SlE, C3H7SlE,

CHFCHSi CH =CHCH SiE, CH CH=CHSiE (CH3)2Si and C2H5SlE. The remaining valences of the silicon atoms are essentially all satisfied by OH groups or combinations of OH groups and SiOSi. The compositions can be made up of one type organosilicon compound or mixtures of two or more types.

The solutions of this invention are readily prepared by adding the corresponding alkoxy or acyloxy silanes such as dimethyldimethoxysilane or propyltriactoxysilane to water and shaking until a uniform solution is obtained. When alkoxysilanes are employed it is advantageous to use a small amount of a weak acid such as acetic acid in order to hasten hydrolysis of the alkoxysilane. This decreases the time necessary to obtain a homogeneous solution.

The treatment of this invention is applicable both to pure wool and to blends of wool with other fabrics. The amount of organosilicon compound actually deposited on the wool runs about percent of the amount in the treating solution. Thus, if one employs a solution containing 2 percent by weight organosilicon compound, about 1.7 percent by weight of the organosilicon compound is actually deposited on the wool.

The solutions can be applied to the fabric in any convenient manner such as by dipping, padding or spraying.

The following examples are illustrative only and should not be construed as limiting the invention which is properly delineated in the appended claims.

Example 1 The following solutions were employed in this example:

(1) 2 parts by weight of dimethyldimethoxysilane were mixed with 98 parts by weight water containing .1 part by weight acetic acid until a homogeneous solution was obtained.

'(2) 2 parts by weight of propyltrimethoxysilane was mixed with 98 parts by weight water containing .1 part by weight acetic acid until a homogeneous solution was obtained.

Each solution was sprayed onto the various garments shown below and the garment was steam pressed While wet for one minute to set a crease and thereafter dried for one hour at 150 F. The garments treated were:

100 percent wool flannel dark olive trousers,

100 percent wool gabardine brown trousers,

100 percent worsted wool charcoal gray trousers,

100 percent wool novelty weave olive green skirt and 100 percent wool plain weave brown plaid skirt.

In each case there was no objectionable odor or undesirable color change in the fabric.

The garments were worn by individuals and dry cleaned several times by commercial techniques. The crease remained intact for an equivalent of two or three seasons of wear. These tests show that the treatment was successful in giving a permanent crease to the wool.

Example 2 W001 gabardine and wool flannel fabrics were treated with 2 percent by weight solutions 1 and 2 of Example 1 in the following manner. The fabrics were padded at 40 psi. from the aqueous baths. Immediately upon removal from the bath the samples were dried 10 minutes at F. Three days later the samples were sprayed with tap water, folded and steam pressed one minute to set a crease. The samples were placed in an air circu lating oven and dried 30 minutes at 150 F.

The permanence of the crease in each case was then checked and found to be satisfactory but not as good as in Example 1.

Example 3 The procedure of Example 1 was repeated employing a solution prepared by dissolving two parts by weight ethyltrimethoxysilane in the place of the methyltrimethoxysilane. A permanent crease was obtained.

Example 4 Equivalent results are obtained when vinyltriacetoxysilane, allyltrimethoxysilane and ethylmethyldimethoxysilane are employed in the procedure of Example 1.

That which is claimed is:

1. The method of imparting a permanent crease to a wool fabric which comprises applying to the fabric a water solution of an organosilicon compound selected from the group consisting of highly hydroxylated silanol and siloxanol organosilicon compounds in which there is an average per silicon atom of from 1 to 2 aliphatic hydrocarbon radicals of from 1 to 3 inclusive carbon atoms attached to the silicon through carbon-silicon bonds, there being on the average no more than 3 carbon atoms per silicon, the remaining valences of the silicon atom being satisfied by substituents selected from the group consisting of hydroxyl radicals and oxygen atoms of SiOSi linkages, there being from .1 to percent by weight of said organosilicon compound based on the weight of the solution and thereafter creasing the fabric under heat and pressure.

2. The method of imparting a permanent crease to a wool fabric which comprises applying to the fabric a water solution of an organosilicon compound selected from the group consisting of highly hydroxylated silanol and siloxanol organosilicon compounds in which there is an average per silicon atom of from 1 to 2 aliphatic hydrocarbon radicals attached to the silicon through carbon-silicon bonds, said radicals having from 1 to 3 inclusive carbon atoms and there being on the average no more than three carbon atoms per silicon, the remaining valences of the silicon atoms being satisfied by substituents selected from the group consisting of hydroxyl radicals and oxygen atoms of SiOSi linkages, there being from .1 to 10 percent by Weight of said organosilicon compound based on the weight of the solution and thereafter creasing the fabric under heat and pressure while still wet with the solution.

3. The method in accordance with claim 1 in which the hydrocarbon radical is methyl.

4. The method in accordance with claim 2 in which the hydrocarbon radical is methyl.

5. The method in accordance with claim 1 wherein the hydrocarbon radical is propyl.

6. The method in accordance with claim 2 wherein the hydrocarbon radical is propyl.

References Cited UNITED STATES PATENTS 2,634,285 4/1953 Rust et al 117139.4 X 2,974,432 3/1961 Warnock et a1. 11710 X 3,032,442 5/1962 Roth 1l7139.4 3,059,990 11/1962 Koenig et al. 117l1 X 3,065,111 11/1962 Reeves et al 11714l X WILLIAM D. MARTIN, Primary Examiner.

MURRAY KATZ, Examiner.

T. G. DAVIS, Assistant Examiner. 

1. THE METHOD OF IMPARTING A PERMANENT CREASE TO A WOOL FABRIC WHICH COMPRISES APPLYING TO THE FABRIC A WATER SOLUTION OF AN ORGANOSILICON COMPOUND SELECTED FROM THE GROUP CONSISTING OF HIGHLY HYDROXYLATED SILANOL AND SILOXANOL ORGANOSILICON COMPOUNDS IN WHICH THERE IS AN AVERAGE PER SILICON ATOM OF FROM 1 ALPHATIC HYDROCARBON RADICALS OF FROM 1 TO 3 INCLUSIVE CARBON ATOMS ATTACHED TO THE SILICON THROUGH CARBON-SILICON BONDS, THERE BEING ON THE AVERAGE NO MORE THAN 3 CARBON ATOMS PER SILICON, THE REMAINING VALENCES OF THE SILICON ATOM BEING SATISFIED BY SUBSTITUENTS SELECTED FROM THE GROUP CONSISTING OF HYDROXYL RADICALS AND OXYGEN ATOMS OF SIOSI LINKAGES, THERE BEING FROM 9U TO 10 PERCENT BY WEIGHT OF SAID ORGANOSILICON COMPOUND BASED ON THE WEIGHT OF THE SOLUTION AND THEREAFTER CREASING THE FABRIC UNDER HEAT AND PRESSURE. 